The Collaborative Perinatal Project (CPP) is a rich data set for the investigation of a variety of topics related to maternal and child health. Recent projects have also begun to utilize the serum collected from pregnant women and their neonates as part of this study, which, along with data collected as for the original study and subsequently, provides a unique resource. Areas investigated in FY 04 include, time required to become pregnant and adverse outcomes of the pregnancy, statistical issues in the analysis of correlated repeated pregnancies to the same woman, maternal serum estrogen and androgen levels and cryptorchidism in male infants, maternal exposure to SV-40 virus during pregnancy and childhood cancer, maternal obesity and twinning, perinatal risk factors for subsequent adult-onset schizophrenia. In the latter study, over 150 individuals from the Providence and Boston sites of the CPP who developed schizophrenia as adults were identified and matched to over 300 cohort members who did not have significant psychiatric pathology. Evidence of hypoxia, viral infection, and immune activation was sought in maternal and umbilical cord serum. Analyses begun in 2004 include the maternal obesity and twinning, maternal smoking and childhood growth, and perinatal risk factors for childhood cancer.